Logical units and target ports on IBM FlashSystem systems
For IBM® FlashSystem™, logical units are enumerated devices that have the same characteristics as LUNs.
LUNs
The IBM FlashSystem system has a maximum LUN size of 40 TB.
The IBM FlashSystem system can export 512 LUNs to the Storwize® V3500 system, which is the Storwize V3500 limit. Storwize V3500 supports greater than 2 TB LUNs.
LUN IDs
The IBM FlashSystem system identifies exported logical units through SCSI identification descriptor type 3. The 64-bit NAA IEEE Registered Extended Identifier (NAA=6) for the logical unit is in the form 6-OUI-VSID. For example, the model 9840-AE1 IEEE company ID is 005076 (IBM). The remaining part of the company ID is a vendor-specific ID.
# lsmdisk 121
id 121
name mdisk121
status online
mode managed
mdisk_grp_id 8
mdisk_grp_name texan2
capacity 50.0GB
quorum_index
block_size 512
controller_name texan2
ctrl_type 4
ctrl_WWNN 500507605EBFECC0
controller_id 19
path_count 32
max_path_count 32
ctrl_LUN_# 000000000000000D
UID 6005076001810000000000001900001b00000000000000000000000000000000
preferred_WWPN
active_WWPN many
fast_write_state empty
raid_status
raid_level
redundancy
strip_size
spare_goal
spare_protection_min
balanced
tier generic_hdd
slow_write_priority
fabric_type fc
site_id
site_name
#
IBM configuration, logical drives, and hosts
svctask mkarray -level raid0/5
A storage pool is provisioned automatically from which the volumes can be provisioned and presented to Storwize V3500.
Generally, it is best to provide a few large LUNs to Storwize V3500 (4 or 8) from the available capacity.
http://www.redbooks.ibm.com/redbooks.nsf/redbookabstracts/tips1079.html?Open&c4#contents
LUN presentation
svctask chsystem -openaccess off
Special LUNs
There are no special considerations for logical unit numbering. LUN 0 can be exported where necessary.
Target ports
An IBM FlashSystem storage system can have a total of 16 8 GB Fibre Channel ports.
# lscontroller
id controller_name ctrl_s/n vendor_id product_id_low product_id_high
19 texan2 000060400000-0000-0 IBM FlashSys tem-9840
# lscontroller 19
id 19
controller_name texan2
WWNN 500507605EBFECC0
mdisk_link_count 15
max_mdisk_link_count 512
degraded no
vendor_id IBM
product_id_low FlashSys
product_id_high tem-9840
product_revision 1103
ctrl_s/n 000060400000-0000-0
allow_quorum yes
fabric_type fc
site_id
site_name
WWPN 500507605EBFECE4
path_count 120
max_path_count 4096
WWPN 500507605EBFECC4
path_count 120
max_path_count 4096
WWPN 500507605EBFECD4
path_count 120
max_path_count 4096
WWPN 500507605EBFECF4
path_count 120
max_path_count 409
#
5005076SSSSSSSPP
5 - IEEE 803.2 ID NAA format,
005076 - IEEE unique VSID for IBM. (common with SVC)
SSSSSS - unique vendor-supplied serial number for the device.
PP - vendor specific code used to identify specific ports
WWNN 500507605EBFF2C0
WWPN 500507605EBFF2E1
WWPN 500507605EBFF2D1
WWPN 500507605EBFF2C1
WWPN 500507605EBFF2F1
LU access model
All systems are Active/Active. To avoid an outage from system failure, cross connect the ports across Fibre Channel switches. Because all IBM FlashSystem storage systems are equal in priority, there is no benefit to using an exclusive set for a specific LU.
LU preferred access port
There are no preferred access ports on the IBM FlashSystem system as all ports are Active/Active across all systems.
Detecting Ownership
Detecting ownership does not apply to IBM FlashSystem storage arrays.